BSUN X Linear Switch Review

Hi everyone, this is Dashan writing. This is my first ever switch review article, and I would like to thank you in advance before you read it!

As some of you might know, I am the owner of a custom mechanical keyboard vendor shop called Unikeyboards. Although I am indeed related to the keyboard business, I would like this to be a purely “personal” review and information-sharing blog. I will not be focusing on reviewing switches that are listed in my store for sale, and the purpose of writing switch reviews will not mainly be for selling my own products. My wish is to set out from my perspective as a keyboard enthusiast, a switch collector, and a switch enjoyer. I will be sharing my knowledge about manufacturers/factories, switch materials, moldings, switch design, and prodcution in my articles. Most importantly, the switches I am going to review are the ones that I personally love! Anyway, I hope everyone would enjoy this review, and before it is too late, let’s get started.

BSUN

If I am going to talk about the X Switches, I cannot leave BSUN aside. As a manufacturer that has been in this game for long enough, BSUN seems to be remaking its appearance in the year of 2023 and has been bringing a variety of new stuff to the public.

During the “pre-historic” time, a time when JWK, Tecsee, and Gateron were in power (they still are), most popular custom switches were being sold between the price point of 0.6-0.8 USD each. Unless you were looking for a budget option such as the Gateron KS-3 or the JWICK Black switches, you would think that kind of a price is normal, and you would go for them without a question. I know I would at the time. However, things in China were starting to shift a little with the presense of so many new BSUN switches in year 2023. People were starting to quesiton the old pricing system of JWK, Tecsee, Gateron, and Kailh and asking whether they truly live up to their values. BSUN set up a standard for its vendors and the individual designers who partnered with them; The rule was that the retail price of BSUN switches shouldn’t be too high or too low, and it was fixed to be around 0.45 USD each. The reason was that such a price point is afforadable to most people, and it would prevent a low-price compititon in the market. So far, it seems to be a good pricing strategy as enthusiasts enjoy their fair priced products and vendors wouldn’t worry too much about competitors lowballing them.

BSUN, also known as YOK, was the factory that manufactured the famous Holy Panda clones, or upgrades one might argue: the YOK Panda switches. This happened in the year 2019, and BSUN/YOK “disappeared” for a while after that. Almost 3 years later, during December of 2022, BSUN/YOK reintroduced themselves with the release of a new switch called the OWLab London Fog switches. Many of you know this switch, and I believe many of you are using this switch when you are reading this. The release of London Fog switches became a turning point for BSUN as they gained enough publicity and sent out a welcome message to the keeb world saying “We are back in the market “. Since then, numerous BSUN switch projects led by different individual designers kept rolling out. Some of the custom switches that BSUN released including the Soya Milk switches, Aniya switches, and of course our protagonist today, the BSUN X Switch.

X

Finally, the X Switch we are talking about. It was one of the earliest BSUN custom switches that got into the market. With its IC post being released on March 19th on Zfrontier, it gained quite a popularity in China. The two most important reasons here are its choice of materials and impoved factory lubrication.

Materials

To my knowledge, the X switch was the first ever BSUN switch, or even the first switch, that utilized a full POK housing. POK, or polyketone, is a non-proprietory material which got introduced to the custom switch market only recently. It has a friction coefficient of 0.04 (The lower the better) which is only higher than LY (0.03) making it the top 2 smoothest material used to make switches. It is also super durable as its wear resistance is 14 times stronger than POM. Its shock resistance is 2.3 times better than Nylon and 1.4 times better than POM. In conclusion, the POK material is perfect for making switches as it is smooth, durable, and stable.

Oh my bad, I only talked about the housing material of the X switch, but what is the stem material? The stem material is actually LY, and yes, I just said in the last paragraph that it is the smoothest material so far in switch manufacturing. When you combine the top two smoothest materials in one switch, what you get the a super smooooth switch, and that is what the X switches are.

Factory Lubrication

The factory lubrication of the X Switches are precise and way better than its BSUN predecessors such as the London Fog switches which are known for their problematic factory lube job. The X Switches are lubed with a mix of 205g0 and 105g0 on its stem legs and bottom housing rails. Its stem and spring are lubed using PTFE, or the dry lube technique. If you look at the picture below, you would see directly what its factory lubrication is like.

To me personally, the factory lube is quite well-applied. I have already spent about three months of time with the X Switches, and they work super great. Why I did not say they are perfect? Well, among the 87 that I installed on my keyboard, about 5 of them ran into some issues. What happened was that these 5 switches became mushy and sticky after 1-2 days of use, and it was because they were over-lubed which caused the lube to pool in the stem hole. I had to use a Q-Tip to clean these 5 switches to keep using them. This was the old issue that existed on the London Fogs, but I have to say there were significant improvement as there were about 25 London Fog switches that I used ran into the same problem. Maybe it is simply related to chance or luck? Maybe. I will talk about this more in my future BSUN switch reviews. Otherwise, BSUN’s current factory lube job is acceptable as it is really there and does make the switches smoother. You might need to spend another 5 minutes to get a few of them straight before getting hazard free, but it has been way better than before.

Moldings

Regarding the molds of the X Switch, I have not much to say about them. Because POK and LY were both new materials for BSUN at the time, the housing and the stem were using brand new molds developed by BSUN to fit the characteristics of the two new materials. If you look closely at the housing and the stem of the X Switch and compare them to other BSUN switches, you will see that they are not that much different from each other.

Subjective Ideas

The X Switches are probably one of the smoothest switches I have ever used in my two years of keyboard life. If you hold them next to your ear and press them slowly, you will hear a minimum sliding noise. There is no obvious spring or leaf ping thanks to BSUN’s new moldings. When typing on them, there is zero scratchy feeling and no extra crap sound other than the stem hitting the bottom and the top housing. It is close to being pure.

Regarding the typing feel, thanks to the LY stem and POK housing, the smoothness of the switch is not a thing to be worried about at all. During my time of using these switches, sometimes I even think they are a bit too smooth for my taste as they can feel a bit “empty” if you know what I mean by that; It feels like the stem is traveling in air without much friction, and that creates a kind of uncertainty when typing. My fingers feel lost and it is like I am typing on air. It may sound inordinate by putting it this way, but it is really that smooth. Also, because it has a flat stem pole instead of a round one, the bottom-out is just stiff enough but not too harsh. It is a nice balance between the materials and the stem pole design which created a switch with concentrated and clean bottoming out and rebound.

Regarding the sound, the X Switches just have the type of sound I like. I am a member of the clack clan, and I am on a search for switches that are clackier and louder. Although the X switches are not very loud, they are indeed clacky to my ears. There are a few reasons to this; One of the most important ones is of course the long pole. The second reason is its choice of materials. Thirdly, it is because the flat stem pole, and the flat upper stem slider design which come in aid to help the bottom out and rebound sound more concentrated.

In conclusion, the switch’s overall sound and feel are great for my personal taste, and the they go well with aluminum plates. You would love them if our preferences are mutual. I would not recommend them to you if you specifically like softer bottom-out and thocky sound.

X Switch Specs

Switch type: Linear
Manufacturer: BSUN/YOK
Stem material: Modified LY
Top and Bottom Housings: POK
Operating Force: 45g
Bottom-out Force: 52g
Pre-travel: 1.6mm
Total Travel: 3.5mm
Spring: 21mm single-stage extended spring

Ratings

Aesthetics: 10/10

Sound: 8/10

Bottom-out: 9/10

Rebound: 10/10

Typing Feel: 8/10

Smoothness: 9/10

Spring: 6/10

Extra Comments

If the spring was changed to a double stage 21mm extended spring or a 55-63g bottom-out single stage spring, I think I will love the switches more. The 21mm single stage spring with a 52g bottom-out is a bit too light and the recoil is not as snappy as I would prefer
The designer released a V2 of the X Switch only 1 month after the V1. The only difference with the V2 was that the top housing material was changed to POM, and to be honest, besides it making the switch less smooth, there wasn’t much differences.